Multistage centrifugal pump



E. N. MACKLEY MULTISTAGE CENTRIFUGAL PUMP Filed Jan. 22 1923 Few. f

lnvervor I my (2% @MAW-LL Patented Nov. 18, 1924.

1;; s s t EDWARD NORMAN MACKLEY, OF NEWC ASTLE-UPON-TYNE, ENGLAND.

iMULTISTAGE CENTRIFUGAL PUMP.

Application filed January 22, 1923. Serial No. 614,253.

To all whom, it may concern:

Be it known that I, EDWARD NORMAN MACKLEY, a subject of the King of Great Britain and Ireland, residing in the city and county of Newcastle-upon-Tyne, England, have invented certain new and useful Improvements in and Relating to Multistage Centrifugal Pumps, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to multi-stage centrifugal pumps wherein the water from the impeller is delivered into a guide passage or into a' series of guide passages in the diffuser whereby the kineticenergy of the water is converted into pressure energy or "head". \Vhere a series of volute guide passages are provided in the diffuser, the pumps are generally known as turbine pumps. The object of the present invention is to provide an improved construction wherein the assembly of the usual elements or sections, each of which comprises a diffuser and a diaphragm, in proper relative position in the pump casing and their withdrawal from one end of said casing is facilitated.

In a pump in accordance with my invention, the diffuser and diaphragm forming each element or section are separately bolted together, and each elementis provided with one or more dowels-or the like projecting endwise, the dowel or dowels of the element next the stationary end plate or diaphragm at one end of the pump casing being adapted to enter a corresponding hole or holes therein and the dowel or dowels of the succeeding elements being adapted to enter a corresponding hole or holes in the elements next nearer to said end plate, thus ensuring correct registration of the elements when same are being assembled in the pump casing and preventing rotation of the elements when the pump is in operation, and, to facilitate withdrawal of the elements, each element is made of slightly larger diameter than the one next nearer to the said end plate and the interior of the cylindrical pum casing is correspondingly stepped so that, when being withdrawn, each element bears only on its own step and can be freely withdrawn immediately it is clear of its step. In this way the withdrawal of the elements nearest the fixed end plate is greatly facilitated, the usual key which extends the full length of the casing being dispensed with and the liability of damage to the interior of the pump casing by scraping of the edges of the elements thereagainst being greatly minimized. Preferably the dowels for ensuring registration and nonrotation of the elements are constituted by providing one or more of the bolts or the like which connect the diffuser to the diaphragm of each element with a dowel-like head, and the holes for receiving said dowellike head may be a continuation of the threaded holes in the diaphragm for the bolts, or maybe formed in the ends of said bolts which, in this case, are extended so as to pass fully through the diaphragm. As will be obvious. the position of the dowels and holes may be reversed.

I will fully describe my invention with reference to the accompanying drawings wherein Figure 1 is an elevation, partly in section, of a six-stage centrifugal or ,turbine pump in accordance therewith, Figure 2 is a part sectional elevation to an enlarged scale illustrating the connection of the diffusers to the diaphragm, and Figures 3 and 4; are similar views to Fig. 2 illustrating modifications. Figure 5 is an end view of one of the diffusers with the impeller removed.

Referring to the drawings, in the construction illustrated in Figs. 1, 2 and 5, the diffuser a and the diaphragm b, which together form each element or section of the pump, are secured together by bolts 0, of which there may, for example, be four or six (as shown), suitably spaced around the elements. The bolts 0 pass through holes 0 (Fig. 5) in the partitions m between the volute guide passages 11. of the diffuser a. a (Fig. 1) are the impellers. The diffuser and diaphragm of each element are of equal diameter but the diameters of the elements are successively increased, that of the element nearest the stationary end plate or diaphragm (Z at the left of the cylindrical pump casing a being the smallest. The liner f of the casing e is provided internally with steps 9 corresponding to the diameters of the elements a, b. If desired, the liner f may be omitted and the steps formed in the bore of the casing c itself. It will be seen that the usual key is dispensed with and the elements (1-, b can be successively inserted into or withdrawn from the casing c with ease as the diffuser a of each element engages only its own step 5! and can be freely slidden past the steps preceding its own step. The likelihood of the elements scraping against and damaging the bore of the easing is thus greatly minimized and the fitmentand withdrawal of the elements facilitated. Moreover the separate bolting together of the diffuser and diaphragms of each element tends to improve the watertightness of the construction. Should leakage occur around the bolt of one element,

it is confined thereto and does not spread from one end to the other of the elements as is frequent where one bolt runs right through all the elements which is the construction hitherto usually adopted. It will be noticed that a clearance is shown between the diaphragm b and the stepped bore of the liner f. This clearance is preferable but not essential, and if desired, the step 9 can be continued parallel throughout the whole depth of one element, as shown in Fig. 4.

Each element a, b is provided with a dowel h projecting from one end face and with a hole j in the other end face to receive the dowel of the next element. Conveniently and as shown, the dowel h is formed integral with the head of one of the bolts 0 of each element, but, if desired, the dowels may be provided separately from the bolts. More than one dowel may be provided'on each element. The hole in each element may be specially provided in the diaphragm b as shown in Fig. 2, or it may be formed by a plain extension of the tap for one of the bolts 0 of each element as shown in Fig. 3, or the bolt 0 may be extended fully through the diaphragm b and the hole provided in its endas shown in Fig. 4. A hole is is provided in the end plate d to receive the dowel of the element nearest thereto.

When assembling the elements, correct registration is ensured by the engagement of the dowels h with the holes j throughout the assemblage of the elements, and rotation of the elements is prevented by the engagement of the dowel h ofthe element nearest the stationary end plate 0! with the hole A: therein.

emme As will be readily understood, the position of the dowels h and holes j may be reversed, i. e. the dowels may be on the end faces of the'diaphragm b and the holes in the end faces of the diffusers a or in the heads of the bolts 0 therein, the end plate 01 being provided with a dowel instead of the hole What lf claim and desire to secure by Letters Patent is 1. A multi-stage centrifugal pump comprising a casing, a plurality of elements therein each consisting of an impeller, a diffuser and a diaphragm, means positively attaching together the diffuser and diaphragm of each element, end plates for said casing, and means coacting with one end plate but independent-of the casing for ensuring correct registration of the elements when assembled in the casing, which means also serves toprevent rotation of the elements when the pump is in operation.

2. A multi-stage centrifugal pump comprising a casing, a plurality of elements therein each consisting of an impeller, a diffuser and a diaphragm, bolts attaching together the diffuser and diaphragm of each element, holes in the side faces of said elements, and endwise projecting members on, the side faces of said elements adapted to enter said holes in the abutting elements when the elements are assembled in the casing. i

3. A multi-stage centrifugal pump comprising an internally-stepped cylindrical casing, a plurality of elements therein each consisting of an impeller, a diffuser and a diaphragm, means positively attaching together the diffuser and diaphragm of each element, and means for ensuring correct registration of the elements when assembled in the casing which means also serve to pre vent rotation of the elements when the pump is in operation, said elements having successively increasing diameters in the direction in which they are removed from the internally-stepped cylindrical casing.

lln testimony whereof, I affix my signature.

EDWARD NORMAN MACKLEY. 

